TY - JOUR
T1 - Structural information on proteins obtainable from small-angle X-ray scattering with heavy-atom labeling. Application to solubilized bacteriorhodopsin
AU - Kataoka, M.
AU - Nakasako, M.
AU - Tokunaga, F.
N1 - Funding Information:
The authors express their sincere thanks to Drs T. Ueki and Y. Inoko of Osaka University for fruitful discussions. They are also grateful to the members of the SAXES working group for their assistance with the SAXS experiment and to the staff of the Photon Factory for their cooperation. This work was partly supported by grants-in-aid from the Ministry of Education, Culture and Science to MK (Nos. 5908724 and 61780072). The SAXS experiment was performed with the approval of the Photon Factory Program Advisory Committee (proposal Nos. 84-007 and 86-028).
Publisher Copyright:
© 1988, Wiley-Blackwell. All rights reserved.
PY - 1988
Y1 - 1988
N2 - The heavy-atom labeling method is applied to small-angle X-ray scattering (SAXS) based on contrast variation in order to derive information on the inner structure of proteins. The formulation of the contrast variation is extended to express explicitly the contribution of the bound heavy atoms to SAXS. The present method reveals two important features concerning bound heavy atoms, namely their number and their distribution. The application of this method to solubilized bacteriorhodopsin (bR) with iodination revealed the following characteristics of structure. The number of bound iodine atoms is 20, indicating that the solubilized bR is composed of a trimer of bR molecules. The mean square distance between the iodine position and the center of the trimer is about 1660 Å2, indicating that the most active tyrosine residues are located near the outer rim of a bR trimer. The distribution of iodine atoms is symmetric about the center.
AB - The heavy-atom labeling method is applied to small-angle X-ray scattering (SAXS) based on contrast variation in order to derive information on the inner structure of proteins. The formulation of the contrast variation is extended to express explicitly the contribution of the bound heavy atoms to SAXS. The present method reveals two important features concerning bound heavy atoms, namely their number and their distribution. The application of this method to solubilized bacteriorhodopsin (bR) with iodination revealed the following characteristics of structure. The number of bound iodine atoms is 20, indicating that the solubilized bR is composed of a trimer of bR molecules. The mean square distance between the iodine position and the center of the trimer is about 1660 Å2, indicating that the most active tyrosine residues are located near the outer rim of a bR trimer. The distribution of iodine atoms is symmetric about the center.
UR - http://www.scopus.com/inward/record.url?scp=84969375611&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84969375611&partnerID=8YFLogxK
U2 - 10.1107/S002188988800319X
DO - 10.1107/S002188988800319X
M3 - Article
AN - SCOPUS:84969375611
VL - 21
SP - 355
EP - 362
JO - Journal of Applied Crystallography
JF - Journal of Applied Crystallography
SN - 0021-8898
IS - 4
ER -